1. Field of the Invention
The present invention relates to a letter producing system, which includes a printing unit for performing printing on printing paper sheets and an inserting and sealing unit for producing a letter by making an envelope from a printing paper sheet subjected to printing at the printing unit and inserting and sealing another printing paper sheet subjected to printing in the envelope. In particular, the present invention relates to control of timing of output of the first printing paper sheet from the printing unit to the inserting and sealing unit.
2. Description of the Related Art
In recent years, along with the increased use of letters, such as advertising letters, various letter producing systems are proposed, which automatically performs printing on printing paper sheets with a printing unit, makes envelopes using the printed printing paper sheets and inserts and seals each enclosure in each envelope.
In such a letter producing system, specifically, each printing paper sheet for envelope and each set of printing paper sheets for enclosure subjected to printing and outputted from the printing unit are received by an inserting and sealing unit. At the inserting and sealing unit, the printing paper sheet for envelope is folded in three, for example, to form an envelope, and the set of printing paper sheets for enclosure, which is also folded in three, for example, is inserted and sealed in the envelope, thereby producing a letter.
The letter producing system, as described above, includes a mechanical mechanism for folding the printing paper sheet for enclosure and the printing paper sheet for envelope, a mechanical mechanism for inserting the printing paper sheet for enclosure in the envelope, etc. Such mechanical mechanisms need to be initialized depending on the size and the type of fold of the printing paper sheet for enclosure and the printing paper sheet for envelope before output of the printing paper sheets from the printing unit to the inserting and sealing unit is started.